/*
 * Copyright 2011-2013 Blender Foundation
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#ifndef __TILE_H__
#define __TILE_H__

#include <limits.h>

#include "render/buffers.h"
#include "util/util_list.h"

CCL_NAMESPACE_BEGIN

/* Tile */

class Tile {
 public:
  int index;
  int x, y, w, h;
  int device;
  /* RENDER: The tile has to be rendered.
   * RENDERED: The tile has been rendered, but can't be denoised yet (waiting for neighbors).
   * DENOISE: The tile can be denoised now.
   * DENOISED: The tile has been denoised, but can't be freed yet (waiting for neighbors).
   * DONE: The tile is finished and has been freed. */
  typedef enum { RENDER = 0, RENDERED, DENOISE, DENOISED, DONE } State;
  State state;
  RenderBuffers *buffers;

  Tile()
  {
  }

  Tile(int index_, int x_, int y_, int w_, int h_, int device_, State state_ = RENDER)
      : index(index_), x(x_), y(y_), w(w_), h(h_), device(device_), state(state_), buffers(NULL)
  {
  }
};

/* Tile order */

/* Note: this should match enum_tile_order in properties.py */
enum TileOrder {
  TILE_CENTER = 0,
  TILE_RIGHT_TO_LEFT = 1,
  TILE_LEFT_TO_RIGHT = 2,
  TILE_TOP_TO_BOTTOM = 3,
  TILE_BOTTOM_TO_TOP = 4,
  TILE_HILBERT_SPIRAL = 5,
};

/* Tile Manager */

class TileManager {
 public:
  BufferParams params;

  struct State {
    vector<Tile> tiles;
    int tile_stride;
    BufferParams buffer;
    int sample;
    int num_samples;
    int resolution_divider;
    int num_tiles;

    /* Total samples over all pixels: Generally num_samples*num_pixels,
     * but can be higher due to the initial resolution division for previews. */
    uint64_t total_pixel_samples;

    /* These lists contain the indices of the tiles to be rendered/denoised and are used
     * when acquiring a new tile for the device.
     * Each list in each vector is for one logical device. */
    vector<list<int>> render_tiles;
    vector<list<int>> denoising_tiles;
  } state;

  int num_samples;
  int slice_overlap;

  TileManager(bool progressive,
              int num_samples,
              int2 tile_size,
              int start_resolution,
              bool preserve_tile_device,
              bool background,
              TileOrder tile_order,
              int num_devices = 1,
              int pixel_size = 1);
  ~TileManager();

  void device_free();
  void reset(BufferParams &params, int num_samples);
  void set_samples(int num_samples);
  bool next();
  bool next_tile(Tile *&tile, int device, uint tile_types);
  bool finish_tile(int index, bool &delete_tile);
  bool done();
  bool has_tiles();

  void set_tile_order(TileOrder tile_order_)
  {
    tile_order = tile_order_;
  }

  int get_neighbor_index(int index, int neighbor);
  bool check_neighbor_state(int index, Tile::State state);

  /* ** Sample range rendering. ** */

  /* Start sample in the range. */
  int range_start_sample;

  /* Number to samples in the rendering range. */
  int range_num_samples;

  /* Get number of actual samples to render. */
  int get_num_effective_samples();

  /* Schedule tiles for denoising after they've been rendered. */
  bool schedule_denoising;

 protected:
  void set_tiles();

  bool progressive;
  int2 tile_size;
  TileOrder tile_order;
  int start_resolution;
  int pixel_size;
  int num_devices;

  /* in some cases it is important that the same tile will be returned for the same
   * device it was originally generated for (i.e. viewport rendering when buffer is
   * allocating once for tile and then always used by it)
   *
   * in other cases any tile could be handled by any device (i.e. final rendering
   * without progressive refine)
   */
  bool preserve_tile_device;

  /* for background render tiles should exactly match render parts generated from
   * blender side, which means image first gets split into tiles and then tiles are
   * assigning to render devices
   *
   * however viewport rendering expects tiles to be allocated in a special way,
   * meaning image is being sliced horizontally first and every device handles
   * it's own slice
   */
  bool background;

  /* Generate tile list, return number of tiles. */
  int gen_tiles(bool sliced);
  void gen_render_tiles();
};

CCL_NAMESPACE_END

#endif /* __TILE_H__ */
